In recent years, minimally invasive surgery has become much more common for performing various types of surgical procedures. This type of surgery has tremendous advantages over traditional “open” surgery in that it does not require a large incision, typically in a person's abdomen, to perform the surgery—something that has revolutionized patient care.
Surgical trocars are commonly used to perform minimally invasive surgery. They are deployed as a means of introduction for cameras and various surgical instruments, such as scissors, graspers, etc., to perform surgery on a patient. A trocar is a medical instrument, typically with a sharply pointed end, often three-sided, that is used with a hollow cylinder or cannula to penetrate walls or bodily cavities. Trocars are also commonly used to introduce ports in the abdomen, such as during laparoscopic surgery. Often, the combined trocar and cannula are referred to as a trocar. The trocar is often passed inside a cannula, and functions as a portal for the subsequent placement of other devices, such as a chest drain, intravenous cannula, etc.
As the insertion of a trocar, even with the skilled selection of a penetration site, involves a risk of damaging blood vessels, internal organs and other interior structures at the insertion site, there have been several attempts in the prior art to improve the imaging capabilities of trocar assemblies. Examples of such prior art imaging trocar systems are described, for example, in U.S. Pat. No. 5,797,944 to Nobles et al., U.S. Pat. No. 5,674,184 to Hassler, Jr., U.S. Pat. No. 5,467,762 to Sauer et al., U.S. Pat. No. 5,591,192 to Privitera et al., and U.S. Pat. No. 5,380,291 to Kaali. These systems typically include a piercing member having an imaging device positioned at the distal tip of the piercing member. While these systems provide improved visualization of bodily tissues during the trocar insertion, they are not useful after the trocar is positioned inside a patient's body and the piercing member with the imaging device is withdrawn from the patient.
There are several prior art trocar systems that provide some visualization capabilities after the trocar has been inserted into a bodily cavity. One of such systems disclosed in US 2011/0160535 to Bayer et al. provides a disposable access port for use in laparoscopic or endoscopic procedures, including a cannula with an embedded camera and a trocar device disposed in the cannula lumen. Once the cannula with the trocar is inserted into a patient's body, the trocar is withdrawn, which urges the camera out of the cannula.
However, these systems still suffer from significant drawbacks. For example, there is usually a single imaging device rigidly affixed on an outer wall of the trocar that is capable of providing only a narrow image of an adjacent tissue site. Also, the prior art imaging devices are not maneuverable and adjustable once positioned inside a patient's body, thus providing limited imaging capabilities.
Therefore, there is a need for a trocar assembly that overcomes the shortcomings of the prior art systems and provides enhanced imaging capabilities after the trocar is inserted and positioned inside the patient's body.